Type-writing machine



(No Model.)

J. BRADY. TYPE WRITING MACHINE.

No. 431,869. 7 Patented July 8, 1890-.

WITNESSES: I/VVEIVTOH UNITED ST TES PATENT OFFICE.

JAMES BRADY, OF BROOKLYN, NEIV YORK, ASSIGNOR TO THE FITCH TYPE- WRITER COMPANY, OF DES MOINES, IOWA.

TYPE-WRITING MACHINE.

SPECIFICATION forming part of Letters Patent No. 431,869, dated July 8, 1890.

Application filed July 10, 1889. Serial No. 317,004. (No model.)

To all whom, it may concern.-

Be it known that 1, JAMES BRADY, a citizen of the United States, residing at Brooklyn, county of Kings, State of New York, have invented certain new and useful Improvements in Type-\Nriting Machines, of which the following is a specification.

Type-writin g machines in common use have a paper-carriage propelled by spring under or over the point of impact of the type upon the platen. A step-by-step escapement releases the carriage and then holds it for each depression of a key-lever. The escapement consists, ordinarily, of a long single or double track and a single or double pawl or stop. Oustomarily where single pawls are used it has had a single tooth to engage a double rack, while when a double pawl or stop is used, one part hinged to the other, each part has had but one tooth. It has, however,been before suggested by me that the double pawl or stop might be provided with a number of teeth on each part. In that case the movable pawl or stop was hinged to the other. It was a toothed segment, and its teeth, as well as those on the fixed pawl or stop and on the rack, were the customary form of gear-teeth. Such form of tooth was advisable in that construction to insure contact of each tooth of the segment-pawl with the rack at each eX- tremity of movement of the latter. The trouble with that form of tooth is that it touches the opposing teeth at but a single point, and wear is rapid. The diminution of wear in these escapements is of considerable importance, for as soon as the teeth get the slightest degree out of alignment freedom of relative movement of the rack and its pawls or stops is impaired or destroyed.

My invention has therefore the following features: I use a single rack and make the teeth of both rack and stop of saw-tooth form, with the working-faces at right angles to the line of movement of the paper-carriage. The stops consist of two short racks, one sliding on the other and guided in a straight path parallel to the long rack by straight guides of any character. The teeth of each rack are in a straight line, so that all of the faces in contact will bear throughout their whole extent, and wear will be distributed over the whole working-face of each tooth. Such teeth, with the ordinary wear occurring on a typewriter, will last almost indefinitely and far outlive an escapement in which each tooth bears but one point of its working-face.

The accompanying drawings show my invention applied to a machine in which the long rack moves with the carriage and the stops are mounted directly on the stationary frame; but it will be apparent that the invention is equally applicable to the reverse case, wherein the long rack is mounted on the stationary frame and the stops are carried by the paper-carriage.

In said drawings, Figure 1 is a sectional elevation of portions of a type-writing machine embodying my invention, all parts being removed which are not necessary to the understanding of my improvement. Fig. 2 is a plan View of the same. Fig. 3 is a plan view, on a larger scale, of the three racks forming the step-by-step escapement. Fig. 4 is an edge View of the sliding short rack. Fig. 5 is a side View or projection of the stirrup hereinafter referred to.

1 is along rack, and 2 3 are two short racks having their teeth arranged to mesh with those of rack 1. The rack 1 has a pivot 4E at each end to hang it from the paper-carriage, and suitable means (not shown) are provided for vibrating or tilting the rack from one to the other of racks 2 3. The teeth of each rack being in a straight line and their bearing or working faces being at right angles to their length, their hearing, and consequently their wear, is distributed over the entire working-surface of every tooth in mesh.

The rack 2 is fixed to any suitable part 5 of the frame, and the rack 3 slides thereon, being 0 guided parallel to rack 1 by screws or studs 6 7 and open slots 8 9. A spiral or other suit able spring 10 is attached at suitable points to the two racks 2 8-as, for example, to screw 6 and pin 11-and tends to impart to rack 3 a 9 5 movement the reverse of that had longitudinally by rack 1 and the paper-carriage. Thus when the rack 1 is vibrated or tilted downward from rack 3 (in engagement with which it normally rests) to rack 2 the rack 3 will be too released and will be pulled or thrown by spring 10 past any desired number of teeth of rack 1 in the direction indicated by the arrowa until arrested byastop-pin 12. When, therefore, the rack 1 is allowed to rise so that it is released by fixed rack 2, it is drawn by customary spring (not shown) in the direction of arrow 12, carrying with it rack 3, with which it meshes immediately on leaving rack 2. This motion of rack 3 is arrested by the impingement of the inner end of slot 8 on stud or screw 7 and movement of rack 1 and papercarriage held until the rack 1 is again vibrated. It will be seen that every tooth of one or other of racks 2 3 has its entire working-face (which I have designated by the letter 0) in contact with the corresponding faces of the teeth of rack 1.

To adjust the throw of rack 3 so that it will travel over a greater or less number of teeth of rack 1, it has two or more seats 13 for the stop-pin 12, and the said pin is carried by a rock-shaft 14, mounted in brackets 15 of the stationary frame. An arm 16 on said rockshaft supports a stirrup or step 17, with which a lever 18 engages. The said lever may have a suitable key, and is so pivoted that its de pression or elevation will throw the pin 12 opposite one or other of seats 13 011 rack 3 and so adjust the throw of said rack. Such an adjustment is especially desirable in adapting the length of feed to the Width of the character printed, as to small or capital lettors. It is obviously immaterial whether the racks be arranged vertical or, as shown, in a horizontal plane. I

Having thus described my invention, the following is what I claim as new therein and desire to secure by Letters Patent:

1. In a type-writing machine, the combination of three straight racks, of which one has an intermittent movement in one direction, the second is stationary as to such movement and is alternately engaged with and disengaged from the first rack bya vibratory movement, and the third has an alternating or reciprocating movement with reference to both the other racks, substantially as set forth.

2. The combination, with the long rack of a step-by-step feed, of two straight racks arranged to engage alternately therewith, all of said racks having parallel plane Workingfaces, substantially as set forth.

The combination of long rack 1, short rack 2, short rack 3, sliding on rack 2 and having a plurality of seats 13, and an adjustable stop-pin 12, adapted to be moved to engage one or other of said seats, substantially as set forth.

JAMES BRADY.

WVitnesses:

HARRY E. KNIGHT, GEORGE S. BELL. 

